diff options
Diffstat (limited to 'Documentation/misc-devices')
| -rw-r--r-- | Documentation/misc-devices/mei/mei-client-bus.txt | 141 | ||||
| -rw-r--r-- | Documentation/misc-devices/mei/mei.txt | 266 |
2 files changed, 0 insertions, 407 deletions
diff --git a/Documentation/misc-devices/mei/mei-client-bus.txt b/Documentation/misc-devices/mei/mei-client-bus.txt deleted file mode 100644 index 743be4ec8989..000000000000 --- a/Documentation/misc-devices/mei/mei-client-bus.txt +++ /dev/null @@ -1,141 +0,0 @@ -Intel(R) Management Engine (ME) Client bus API -============================================== - - -Rationale -========= - -MEI misc character device is useful for dedicated applications to send and receive -data to the many FW appliance found in Intel's ME from the user space. -However for some of the ME functionalities it make sense to leverage existing software -stack and expose them through existing kernel subsystems. - -In order to plug seamlessly into the kernel device driver model we add kernel virtual -bus abstraction on top of the MEI driver. This allows implementing linux kernel drivers -for the various MEI features as a stand alone entities found in their respective subsystem. -Existing device drivers can even potentially be re-used by adding an MEI CL bus layer to -the existing code. - - -MEI CL bus API -============== - -A driver implementation for an MEI Client is very similar to existing bus -based device drivers. The driver registers itself as an MEI CL bus driver through -the mei_cl_driver structure: - -struct mei_cl_driver { - struct device_driver driver; - const char *name; - - const struct mei_cl_device_id *id_table; - - int (*probe)(struct mei_cl_device *dev, const struct mei_cl_id *id); - int (*remove)(struct mei_cl_device *dev); -}; - -struct mei_cl_id { - char name[MEI_NAME_SIZE]; - kernel_ulong_t driver_info; -}; - -The mei_cl_id structure allows the driver to bind itself against a device name. - -To actually register a driver on the ME Client bus one must call the mei_cl_add_driver() -API. This is typically called at module init time. - -Once registered on the ME Client bus, a driver will typically try to do some I/O on -this bus and this should be done through the mei_cl_send() and mei_cl_recv() -routines. The latter is synchronous (blocks and sleeps until data shows up). -In order for drivers to be notified of pending events waiting for them (e.g. -an Rx event) they can register an event handler through the -mei_cl_register_event_cb() routine. Currently only the MEI_EVENT_RX event -will trigger an event handler call and the driver implementation is supposed -to call mei_recv() from the event handler in order to fetch the pending -received buffers. - - -Example -======= - -As a theoretical example let's pretend the ME comes with a "contact" NFC IP. -The driver init and exit routines for this device would look like: - -#define CONTACT_DRIVER_NAME "contact" - -static struct mei_cl_device_id contact_mei_cl_tbl[] = { - { CONTACT_DRIVER_NAME, }, - - /* required last entry */ - { } -}; -MODULE_DEVICE_TABLE(mei_cl, contact_mei_cl_tbl); - -static struct mei_cl_driver contact_driver = { - .id_table = contact_mei_tbl, - .name = CONTACT_DRIVER_NAME, - - .probe = contact_probe, - .remove = contact_remove, -}; - -static int contact_init(void) -{ - int r; - - r = mei_cl_driver_register(&contact_driver); - if (r) { - pr_err(CONTACT_DRIVER_NAME ": driver registration failed\n"); - return r; - } - - return 0; -} - -static void __exit contact_exit(void) -{ - mei_cl_driver_unregister(&contact_driver); -} - -module_init(contact_init); -module_exit(contact_exit); - -And the driver's simplified probe routine would look like that: - -int contact_probe(struct mei_cl_device *dev, struct mei_cl_device_id *id) -{ - struct contact_driver *contact; - - [...] - mei_cl_enable_device(dev); - - mei_cl_register_event_cb(dev, contact_event_cb, contact); - - return 0; -} - -In the probe routine the driver first enable the MEI device and then registers -an ME bus event handler which is as close as it can get to registering a -threaded IRQ handler. -The handler implementation will typically call some I/O routine depending on -the pending events: - -#define MAX_NFC_PAYLOAD 128 - -static void contact_event_cb(struct mei_cl_device *dev, u32 events, - void *context) -{ - struct contact_driver *contact = context; - - if (events & BIT(MEI_EVENT_RX)) { - u8 payload[MAX_NFC_PAYLOAD]; - int payload_size; - - payload_size = mei_recv(dev, payload, MAX_NFC_PAYLOAD); - if (payload_size <= 0) - return; - - /* Hook to the NFC subsystem */ - nfc_hci_recv_frame(contact->hdev, payload, payload_size); - } -} diff --git a/Documentation/misc-devices/mei/mei.txt b/Documentation/misc-devices/mei/mei.txt deleted file mode 100644 index 2b80a0cd621f..000000000000 --- a/Documentation/misc-devices/mei/mei.txt +++ /dev/null @@ -1,266 +0,0 @@ -Intel(R) Management Engine Interface (Intel(R) MEI) -=================================================== - -Introduction -============ - -The Intel Management Engine (Intel ME) is an isolated and protected computing -resource (Co-processor) residing inside certain Intel chipsets. The Intel ME -provides support for computer/IT management features. The feature set -depends on the Intel chipset SKU. - -The Intel Management Engine Interface (Intel MEI, previously known as HECI) -is the interface between the Host and Intel ME. This interface is exposed -to the host as a PCI device. The Intel MEI Driver is in charge of the -communication channel between a host application and the Intel ME feature. - -Each Intel ME feature (Intel ME Client) is addressed by a GUID/UUID and -each client has its own protocol. The protocol is message-based with a -header and payload up to 512 bytes. - -Prominent usage of the Intel ME Interface is to communicate with Intel(R) -Active Management Technology (Intel AMT) implemented in firmware running on -the Intel ME. - -Intel AMT provides the ability to manage a host remotely out-of-band (OOB) -even when the operating system running on the host processor has crashed or -is in a sleep state. - -Some examples of Intel AMT usage are: - - Monitoring hardware state and platform components - - Remote power off/on (useful for green computing or overnight IT - maintenance) - - OS updates - - Storage of useful platform information such as software assets - - Built-in hardware KVM - - Selective network isolation of Ethernet and IP protocol flows based - on policies set by a remote management console - - IDE device redirection from remote management console - -Intel AMT (OOB) communication is based on SOAP (deprecated -starting with Release 6.0) over HTTP/S or WS-Management protocol over -HTTP/S that are received from a remote management console application. - -For more information about Intel AMT: -http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide - - -Intel MEI Driver -================ - -The driver exposes a misc device called /dev/mei. - -An application maintains communication with an Intel ME feature while -/dev/mei is open. The binding to a specific feature is performed by calling -MEI_CONNECT_CLIENT_IOCTL, which passes the desired UUID. -The number of instances of an Intel ME feature that can be opened -at the same time depends on the Intel ME feature, but most of the -features allow only a single instance. - -The Intel AMT Host Interface (Intel AMTHI) feature supports multiple -simultaneous user connected applications. The Intel MEI driver -handles this internally by maintaining request queues for the applications. - -The driver is transparent to data that are passed between firmware feature -and host application. - -Because some of the Intel ME features can change the system -configuration, the driver by default allows only a privileged -user to access it. - -A code snippet for an application communicating with Intel AMTHI client: - - struct mei_connect_client_data data; - fd = open(MEI_DEVICE); - - data.d.in_client_uuid = AMTHI_UUID; - - ioctl(fd, IOCTL_MEI_CONNECT_CLIENT, &data); - - printf("Ver=%d, MaxLen=%ld\n", - data.d.in_client_uuid.protocol_version, - data.d.in_client_uuid.max_msg_length); - - [...] - - write(fd, amthi_req_data, amthi_req_data_len); - - [...] - - read(fd, &amthi_res_data, amthi_res_data_len); - - [...] - close(fd); - - -IOCTL -===== - -The Intel MEI Driver supports the following IOCTL commands: - IOCTL_MEI_CONNECT_CLIENT Connect to firmware Feature (client). - - usage: - struct mei_connect_client_data clientData; - ioctl(fd, IOCTL_MEI_CONNECT_CLIENT, &clientData); - - inputs: - mei_connect_client_data struct contain the following - input field: - - in_client_uuid - UUID of the FW Feature that needs - to connect to. - outputs: - out_client_properties - Client Properties: MTU and Protocol Version. - - error returns: - EINVAL Wrong IOCTL Number - ENODEV Device or Connection is not initialized or ready. - (e.g. Wrong UUID) - ENOMEM Unable to allocate memory to client internal data. - EFAULT Fatal Error (e.g. Unable to access user input data) - EBUSY Connection Already Open - - Notes: - max_msg_length (MTU) in client properties describes the maximum - data that can be sent or received. (e.g. if MTU=2K, can send - requests up to bytes 2k and received responses up to 2k bytes). - - IOCTL_MEI_NOTIFY_SET: enable or disable event notifications - - Usage: - uint32_t enable; - ioctl(fd, IOCTL_MEI_NOTIFY_SET, &enable); - - Inputs: - uint32_t enable = 1; - or - uint32_t enable[disable] = 0; - - Error returns: - EINVAL Wrong IOCTL Number - ENODEV Device is not initialized or the client not connected - ENOMEM Unable to allocate memory to client internal data. - EFAULT Fatal Error (e.g. Unable to access user input data) - EOPNOTSUPP if the device doesn't support the feature - - Notes: - The client must be connected in order to enable notification events - - - IOCTL_MEI_NOTIFY_GET : retrieve event - - Usage: - uint32_t event; - ioctl(fd, IOCTL_MEI_NOTIFY_GET, &event); - - Outputs: - 1 - if an event is pending - 0 - if there is no even pending - - Error returns: - EINVAL Wrong IOCTL Number - ENODEV Device is not initialized or the client not connected - ENOMEM Unable to allocate memory to client internal data. - EFAULT Fatal Error (e.g. Unable to access user input data) - EOPNOTSUPP if the device doesn't support the feature - - Notes: - The client must be connected and event notification has to be enabled - in order to receive an event - - -Intel ME Applications -===================== - - 1) Intel Local Management Service (Intel LMS) - - Applications running locally on the platform communicate with Intel AMT Release - 2.0 and later releases in the same way that network applications do via SOAP - over HTTP (deprecated starting with Release 6.0) or with WS-Management over - SOAP over HTTP. This means that some Intel AMT features can be accessed from a - local application using the same network interface as a remote application - communicating with Intel AMT over the network. - - When a local application sends a message addressed to the local Intel AMT host - name, the Intel LMS, which listens for traffic directed to the host name, - intercepts the message and routes it to the Intel MEI. - For more information: - http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide - Under "About Intel AMT" => "Local Access" - - For downloading Intel LMS: - http://software.intel.com/en-us/articles/download-the-latest-intel-amt-open-source-drivers/ - - The Intel LMS opens a connection using the Intel MEI driver to the Intel LMS - firmware feature using a defined UUID and then communicates with the feature - using a protocol called Intel AMT Port Forwarding Protocol (Intel APF protocol). - The protocol is used to maintain multiple sessions with Intel AMT from a - single application. - - See the protocol specification in the Intel AMT Software Development Kit (SDK) - http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide - Under "SDK Resources" => "Intel(R) vPro(TM) Gateway (MPS)" - => "Information for Intel(R) vPro(TM) Gateway Developers" - => "Description of the Intel AMT Port Forwarding (APF) Protocol" - - 2) Intel AMT Remote configuration using a Local Agent - - A Local Agent enables IT personnel to configure Intel AMT out-of-the-box - without requiring installing additional data to enable setup. The remote - configuration process may involve an ISV-developed remote configuration - agent that runs on the host. - For more information: - http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide - Under "Setup and Configuration of Intel AMT" => - "SDK Tools Supporting Setup and Configuration" => - "Using the Local Agent Sample" - - An open source Intel AMT configuration utility, implementing a local agent - that accesses the Intel MEI driver, can be found here: - http://software.intel.com/en-us/articles/download-the-latest-intel-amt-open-source-drivers/ - - -Intel AMT OS Health Watchdog -============================ - -The Intel AMT Watchdog is an OS Health (Hang/Crash) watchdog. -Whenever the OS hangs or crashes, Intel AMT will send an event -to any subscriber to this event. This mechanism means that -IT knows when a platform crashes even when there is a hard failure on the host. - -The Intel AMT Watchdog is composed of two parts: - 1) Firmware feature - receives the heartbeats - and sends an event when the heartbeats stop. - 2) Intel MEI iAMT watchdog driver - connects to the watchdog feature, - configures the watchdog and sends the heartbeats. - -The Intel iAMT watchdog MEI driver uses the kernel watchdog API to configure -the Intel AMT Watchdog and to send heartbeats to it. The default timeout of the -watchdog is 120 seconds. - -If the Intel AMT is not enabled in the firmware then the watchdog client won't enumerate -on the me client bus and watchdog devices won't be exposed. - - -Supported Chipsets -================== - -7 Series Chipset Family -6 Series Chipset Family -5 Series Chipset Family -4 Series Chipset Family -Mobile 4 Series Chipset Family -ICH9 -82946GZ/GL -82G35 Express -82Q963/Q965 -82P965/G965 -Mobile PM965/GM965 -Mobile GME965/GLE960 -82Q35 Express -82G33/G31/P35/P31 Express -82Q33 Express -82X38/X48 Express - ---- -linux-mei@linux.intel.com |
